Jennifer Lopez's performance in another Simon Cowell-produced talent show on ITV, Britain's Got Talent, earlier this year also prompted complaints, but Ofcom decided not to investigate.

It remains to be seen whether the regulator will decide to launch a formal investigation of Sunday night's performance by Gaga.

An ITV spokeswoman said: "We do not believe Lady Gaga's performance was inappropriate for the family audience of the X Factor Results show, which has an established tradition of featuring performances from the biggest music stars.

"Lady Gaga is well known for her highly individual performance style."

Suzanne Moore: Grayson Perry is right to say the art world has flattened out. The family friendly gyrations on The X Factor have left me in mourning for a time when transgression was not simply a marketing technique